Moscow, to western eyes, does not look much like Rome. But if there is any country in the world where the tug of the Roman ideal can be felt, it is Russia.

Great pretender? Barack Obama seems a modern incarnation of a line of ambitious imperatores whose powers are all too mortal.

When did the Roman empire end? It is still possible to find history books that give a very precise answer to this question. The curtain came down on the Roman empire, so it is usually claimed, on 4 September 476, when a young man by the name of Romulus Augustulus was formally stripped of the imperial purple by a Gothic chieftain and packed off to retirement near Naples. The accident of his name, in this particular version of Rome’s fall, provides the perfect bookend to a thousand years and more of the Roman story. Romulus, after all, had been the founder of the Eternal City, Augustus her first emperor. Now, with the deposition of Augustulus – “the little Augustus” – the line of emperors had come to an end. The light-switch had been turned off. Antiquity was over; the Dark Ages had begun.

In fact, in almost every way that it can be, dating the fall of the Roman empire to a particular day in 476 is wrong. On the most pedantic level, the title “last Roman emperor of the west” should properly belong not to Romulus Augustulus at all, but to a Balkan warlord, named Julius Nepos, who was murdered in 480. Meanwhile, in Rome itself, life carried on pretty much as normal. Consuls continued to be elected, the senate to sit, chariot races to be held in the Circus Maximus. Most saliently of all, in the eastern half of the Mediterranean, the Roman empire was still strong. Ruled from a city pointedly christened the Second Rome, it remained the greatest power of its day. Constantinople had many centuries of life in it yet as a Roman capital.

It turns out, in short, that the fall of Rome is to human history what the end of the dinosaurs is to natural history: the prime example of an extinction that nevertheless, when one looks at it more closely, turns out to be more complicated than one might have thought. If it is true, after all, that birds are, in a sense, dinosaurs, then it destabilises our notion of the asteroid strike at the end of the Cretaceous era as a guillotine dropping on the neck of the Mesozoic. Likewise, the notion of a Romanitas, a “Roman-ness”, surviving into the Middle Ages, and perhaps beyond, upsets the categorisation of the Roman empire that most of us have as a phenomenon purely of the ancient world.

It is important, of course, not to take revisionism too far. Just as a wren is no tyrannosaur, so was, say, the England of Bede incalculably different from the Roman province of Britannia. “Transformation”, the word favoured by many historians to describe the decline of Roman power, hardly does the process justice. The brute facts of societal collapse are written both in the history of the period and in the material remains. An imperial system that had endured for centuries imploded utterly; barbarian kingdoms were planted amid the rubble of what had once been Roman provinces; paved roads, central heating and decent drains vanished for a millennium and more. So, it is not unreasonable to characterise the fall of the Roman empire in the west as the nearest thing to an asteroid strike that history has to offer.

One striking measure of this – the degree to which it was indeed, in the words of the historian Aldo Schiavone, “the greatest catastrophe ever experienced in the history of civilisation, a rupture of incalculable proportions” – is that even today it determines how everyone in the west instinctively understands the notion of empire. What rises must fall. This seems to most of us almost as much a law in the field of geopolitics as it is in physics. Every western country that has ever won an empire or a superpower status for itself has lived with a consciousness of its own mortality.

In Britain, which only a century ago ruled the largest agglomeration of territory the world has ever seen, we have particular cause. Back in 1897, at the seeming pinnacle of the empire on which the sun never set, subject peoples from the across the world gathered in London to mark the diamond jubilee of Queen Victoria. Rudyard Kipling, the supposed laureate of imperialism, wrote a poem, “Recessional”, to mark the occasion – but it was the very opposite of jingoistic. Instead, it looked to the future in sombre and (as it turned out) prophetic terms:

Far-called our navies melt away;On dune and headland sinks the fire:Lo, all our pomp of yesterdayIs one with Nineveh and Tyre!

Today, in Washington, DC, precisely the same anxieties are being aired – and the example of Rome is often explicitly cited. In 2007, the then comptroller general of the US, David Walker, gave a bleak assessment of the nation’s prospects. America, he claimed, was afflicted by precisely the problems that he saw as responsible for the collapse of Rome: “declining moral values and political civility at home, an overconfident and overextended military in foreign lands and fiscal irresponsibility by the central government”.

American self-confidence seems to have clawed back at least some lost ground since then. Nevertheless, pessimism remains the default setting at the moment in both the US and the west as a whole. When a country’s capital city boasts a Senate and a Capitol Hill, the example of Rome’s decline and fall is always going to be lurking somewhere at the back of the mind.

Yet those who assume it to be an inevitable fact of nature that all empires, sooner or later, will come to share the fate of Rome need only look at America’s chief rival for the title of 21st-century hegemon to see that it ain’t necessarily so.

The People’s Republic of China, unlike the states of the modern west, stands recognisably in a line of descent from an ancient empire. Three years ago, a professor at the National Defence University in Beijing – a colonel by the name of Liu Mingfu – published a book about China’s future called The China Dream.

The title was an obvious riff on the ideal of the American dream; but the Chinese equivalent, it turns out, is as much about drawing sustenance from the past as about looking to the future. Unity at home, projection of strength abroad, the organic fusion of soft and hard power: these, according to the colonel, are in the DNA of Chinese greatness. How does he know this? Why, by looking to ancient history – and specifically to the example of Qin Shi Huangdi, the so-called First Emperor, who back in the 3rd century BC united China, embarked on the Great Wall, and established a template of leadership that even Mao admired.

It is as though US commentators, trying to plot a course ahead for their country, were to look to Caesar Augustus as an exemplar. The reason they would never do that is obvious. The US, for all that it has a Senate and a Capitol, is self-consciously a young country, planted in a new world. But China is old, and knows that it is old. Dynasties may have come and gone, waves of barbarians may have washed over it again and again, the emperor himself may have been replaced by a general secretary – but no rupture such as separates Barack Obama from ancient Rome divides Xi Jinping from the First Emperor. The “China dream”, in its essence, is simply the dream that the “Middle Kingdom” will regain what many Chinese see as her ancient birthright: a global primacy, at the heart of world affairs.

There is a taste here, perhaps – just the faintest, most tantalising taste – of a counterfactual: one in which Rome did not fall. That China was able to survive conquest by the Mongols and the Manchus demonstrates just how deep the roots of a civilisation can reach. What about the Romans in the heyday of their empire: did they have the same kind of confidence in the permanence of their empire the Chinese have always had? And if they did – what happened to that confidence?

People in antiquity were certainly aware that civilisations could rise and fall. It is, in a sense, the great geopolitical theme of the Bible. In the Book of Daniel, the prophet dreams that he sees four beasts emerge in succession from a raging sea; and an angel explains to him that each beast represents a kingdom. The fourth beast, so Daniel is told, symbolises the mightiest empire of all; and yet, for all that, it will end up destroyed “and given to the burning flame”. Gold and purple, in the Bible, are cast as merely the winding-sheets of worldly greatness.

The Greeks, too, with the example of the sack of Troy before them, were morbidly aware how impermanent greatness might be. Herodotus, the first man to attempt a narrative of how and why empires succeed one another that did not look primarily to a god for its explanations, bookends his great history with telling passages on the precariousness of civilisations. “Human foundations both great and insignificant will need to be discussed,” he declares at the start of his first book. “Most of those that were great once have since slumped into decline, and those that used to be insignificant have risen, within my own lifetime, to rank as mighty powers. I will pay equal attention to both, for human beings and prosperity never endure side by side for long.”

Then, in the very last paragraph of his history, he provides what is, in essence, the first materialist theory as to why civilisations should succeed and fail. The Persians, having conquered a great empire, want to move from their harsh mountains to a richer land – but Cyrus, their king, forbids it. “Soft lands breed soft men.” It is a perspective that Herodotus has been tracing throughout his account of civilisational vicissitude, using it to explain why the Persians were able to conquer the Lydians, the Babylonians and the Egyptians, only to come to grief against the poverty-stricken but hardy Greeks. Implicit in his narrative, written at a time when Athens was at her peak of glory, is a warning: where other great powers have gone, the Athenians will surely follow.

The Romans signalled their arrival on the international stage by fighting three terrible wars with a rival west Mediterranean people: the Carthaginians. At the end of the third war, in 146BC, they succeeded in capturing Carthage, and levelling it to the ground. This was the great fulfilment of Rome’s military aims. In 216BC Rome had almost been brought to defeat by Hannibal, Carthage’s most formidable general – a brush with civilisational death that her people would never forget.

In these circumstances, the destruction of Rome’s deadliest enemy was an exultant moment. Nevertheless, it is said of the Roman general who torched Carthage that he wept as he watched her burn and quoted lines from Homer on the fall of Troy. Then he turned to a Greek companion. “I have a terrible foreboding,” so he confessed, “that some day the same doom will be pronounced on my country.”

There were many, as the Romans continued to expand their rule across the Mediterranean, who found themselves hoping that the presentiment was an accurate one. Rome was a brutal and domineering mistress, and the increasing number of much older civilisations under her sway unsurprisingly felt much resentment of her autocratic ways. Greek traditions of prophecy began to blend with Jewish ones to foretell the empire’s inevitable doom. “Civil tumults will engulf her people,” so it was foretold, “and everything will collapse.”

A century on from the burning of Car­thage, in the mid-1st century BC, it seemed that these oracles had been speaking the truth. Rome and her empire were engulfed by civil war. In one particular bloody campaign, it has been estimated, a quarter of all citizens of military age were fighting on one side or the other. No wonder that, amid such slaughter, even the Romans dared to contemplate the end of their empire. “The Roman state, just like all states, is doomed to die.” So wrote the poet Virgil amid the horrors of the age.

But the Roman state did not die. In the event, the decades of civil war were brought to an end, and a new and universal era of peace was proclaimed. Rome, and the known world with it, were brought under the rule of a single man, Imperator Caesar Augustus: the first man in what was to be a long line of imperatores, “victorious generals” – “emperors”.

Virgil, perhaps because he had gazed into the abyss of civil war and understood what anarchy meant, proved a worthy laureate of the new age. He reminded the Roman people of their god-given destiny: “To impose the works and ways of peace, to spare the vanquished and to overthrow the haughty by means of war.”

By the time that Rome celebrated its millennium in AD248, the presumption that the city’s rule was eternal had come to be taken for granted by the vast majority of her subjects – most of whom, by this point, regarded themselves as Romans. “Everywhere,” as one provincial put it, addressing the Eternal City, “you have made citizens of those who rank as the noblest, most accomplished and powerful of peoples. All the world has been adorned by you as a pleasure garden.”

In the event, the garden would turn to brambles and weeds. Intruders would smash down the fences. New tenants would carve up much of it between themselves.

Yet the dream of Rome did not fade. Its potency was too strong for that. “A Goth on the make wishes to be like a Roman – but only a poor Roman would wish to be like a Goth.” So spoke Theodoric, successor to the king who had deposed Romulus Augustulus: a man who combined a most German-looking moustache with the robes and regalia of a caesar. He was not the first barbarian to find in the memory of Rome – the splendour of its monuments, the vastness of its sway, the sheer conceit of its pretensions – the only conceivable model for an upwardly mobile king to ape.

Indeed, one could say that the whole history of the early-medieval west is understood best as a series of attempts by various warlords to square the grandeur of their Roman ambitions with the paucity of their resources. There was Charlemagne, who not only had himself crowned as emperor in Rome on Christmas Day AD800, but plundered the city of pillars for his own capital back in Aachen. Then there was Otto I, the great warrior king of the Saxons, a hairy-chested lion of a man, who in 962 was also crowned in Rome. The line of emperors that he founded did not expire until 1806, when the Holy Roman empire, as it had first become known in the 13th century, was terminated by Napoleon.

“Neither holy, nor Roman, nor an empire,” Voltaire quipped. Yet the joke was not quite fair. There had been a time when it was all three. Otto III, grandson and namesake of the old Saxon king, crowned in 996 and charged with the rule of Christendom during the millennial anniversary of Christ’s birth, was nothing if not a Roman emperor.

He lived on the Palatine Hill, just as Augustus had done a thousand years before him; he revived the titles of “consul” and “senator”. He had himself betrothed to a princess from the Second Rome, Constantinople. His death in 1002, before his marriage could serve to join the eastern and western empires, left hanging one of history great “what-ifs”. Otto III’s ambition of reviving the Roman empire had been the great theme of his reign. Tantalising, then, to ponder what might have happened if he had succeeded in joining it to the eastern Roman empire – the empire that, unlike his own, could trace a direct line of descent from ancient Rome.

***

Today, when we use the adjective “Byzantine” to describe this empire, we risk obscuring the degree to which the people we call “Byzantines” saw themselves as Romaioi – Romans. It was not, however, to the Rome of Julius Caesar and Cicero they looked back, but to that of the great Christian emperors: Constantine, the founder of their capital, and Theodosius the Great, who at the end of the 4th century had been the last man to rule both east and west. In that sense, it was indeed the capital of a Roman empire that fell to Mehmet II, the Turkish sultan, when in 1453 he stormed the great walls built by Theodosius’s grandson a thousand years earlier to gird Constantinople, the “Queen of Cities”. It was indeed the last territorial fragment of the Roman empire that was conquered when, in 1461, the tiny Byzantine statelet of Trebizond was absorbed into the Ottoman empire. At last, a story that had begun more than 2,000 years earlier on a hill beside the Tiber was brought to a definitive end by Turkish guns on the shore of the Black Sea.

Or was it? The Turks were not the first to have laid siege to Constantinople. Back in 941, adventurers known as Rus’, Vikings who had travelled the long river-route down from the Baltic to the Bosphorus, had similarly attacked the city. Their assault had failed; but Miklagard, Caesar’s golden capital, continued to haunt their imaginings. In 986, one of their princes sent a fact-finding mission. Volodymyr was the lord of a rough-hewn frontier town named Kyiv – and he had decided that the time had come for him to join the community of nations.

But which community? He had invited Jews to his court; but after questioning them said their loss of Jerusalem was a sign they had been abandoned by God. He had invited Muslims; but was appalled to learn that their religion would not permit him to eat pork or to drink (as he frankly told them, “drinking is the joy of the Rus’ ”). He had sent envoys to the churches of the west; but there, so they reported back, “we saw no beauty”. Only in Constantinople, in the great cathedral of Hagia Sophia, had Volodymyr’s ambassadors discovered a spectacle worthy of their master’s ambitions.

“We knew not whether we were on heaven or on earth. For on earth there is no such splendour or such beauty. We only know that God dwells there among men . . . we cannot forget that beauty.”

So began a commitment on the part of the Rus’ to the Orthodox faith of the Second Rome that was to have enduring consequences into the present. Volodymyr had recently captured from the Byzantines the city of Chersonesus in the Crimea, originally founded as a Greek colony way back in the 6th century BC. He restored it to the emperor; and in exchange, it is said, received baptism in the city, together with the hand of Caesar’s sister. A momentous step. Never before had a Byzantine princess been given in marriage to a barbarian. The precedent it set was one that the Rus’ would never forget. In 1472, almost two decades after the fall of Constantinople to the Turks, the niece of the last emperor of the Second Rome was married to Ivan III of Muscovy. “Two Romes have fallen.” So a Russian monk, in 1510, would gravely tell their son. “The Third Rome, though, stands – nor will there ever be a Fourth.”

***

Moscow, to western eyes, does not look very much like Rome. There is no Senate there, no Capitol Hill. No buildings, as they do in Paris or Washington, seek to ape the look of Augustan Rome. Even so, if there is any country in the world where the tug of the Roman ideal can still be felt as a palpable influence on its leader’s policy, it is Russia. In 1783, when Catherine the Great annexed Crimea, it was in pursuit of a decidedly Roman dream: that of restoring the Byzantine empire under the two-headed eagle on her own banner. “You have attached the territories,” Potemkin wrote to her, “which Alexander and Pompey just glanced at, to the baton of Russia, and Chersonesus – the source of our Christianity, and thus of our humanity – is now in the hands of its daughter.” No one, as yet, has written in quite these terms to Putin; but if someone did, it would not be entirely a surprise.

Today, here in the west, dreams of restoring a Roman empire are gone for good. The shadows they cast are too grim. The most recent political philosophy to be inspired by them, and which even took its name from the bundle of rods with an axe carried by the bodyguards of Roman magistrates, was developed only in the 20th century: fascism. With Mussolini and Hitler, the millennia-old tradition in the west of looking to the Roman empire for a model reached a hideous climax – and then expired.

Yet if the First Rome is long gone, and the Second Rome, too, the Third, it turns out, retains an unexpected capacity to lurch up out of its grave. Even in the 21st century, the Roman empire clings to a certain ghoulish afterlife yet.

Tom Holland’s translation of Herodotus’s “Histories” is published by Penguin Classics (£25)